Electromagnetic compatibility management for fast diagnostic design

Abstract

This article presents an overview of electromagnetic compatibility (EMC) management for fast diagnostic design. We will present and detail the classical approach in EMC. This approach can be successfully applied for installations where a single engineering entity has the authority to prescribe and enforce a certain compatibility level. Most of the time, strict application of generic standards is required for fast diagnostics. Nethertheless, the pulse perturbation must be synchronized to the fast diagnostic operation. Some “traditional” techniques, such as star-earthing and bonding cable screens at one end, have been shown to be inadequate for fast diagnostic design. Our laser facility, the LIL, will be able to focus up to 60 kJ into a volume of less than 1 mm3. We have to evaluate the electromagnetic pulse (EMP) where diagnostics, cables, and oscilloscopes will be installed. We performed electromagnetic measurements inside and outside the OMEGA target chamber. The electromagnetic pulse generated by the target chamber contains very high frequency components above 1 GHz. The electric field is around a few kV/m outside and goes up to 20 kV/m inside the target. We designed a specific electromagnetic probe for pulse measurement with a rise time down to 100 ps. An ultrashort rise time EMP bench test was built to test apparatus before installation around a target chamber. It produces an electric field higher than 5 kV/m with a rise time under 100 ps.